Røssåga Main Beam sets Norwegian Milestone

Robbins Machine is the first TBM to break through in Two Decades

A crowd of crew members gathered to celebrate in front of a newly emerged hard rock TBM on December 10, 2015 in northern Norway, but their celebration was about more than just a breakthrough.  The 7.2 m (23.6 ft) diameter Robbins Main Beam machine had traversed incredibly hard rock, water inflows, and more to become the first TBM in the country to break through in over 20 years. 

                            

The LNS and Robbins crew celebrate Norway’s first TBM breakthrough in 23 years at the Røssåga Hydroelectric Project. Photo credit: LNS

                        
The 7.4 km (4.6 mi) long headrace tunnel for the Røssåga Hydroelectric Project offered up a number of challenges to the crew. “We bored through hard, quartz-rich rock with rock strengths up to 300 MPa (43,500 psi) UCS and softer karstic limestone with water ingress,” explained Tobias Andersson, TBM Manager for contractor Leonhard Nilsen & Sønner (LNS).  Despite the geological challenges, the TBM performed very well and achieved a record production of 250 m (820 ft) advance in one week, as well as a high of 54 m (177 ft) in one day.  Advance rates consistently ranged from 180 to 200 m (590 to 660 ft) per week throughout the project.

The hard and abrasive rock required both fine-tuning of the disc cutters and a learning curve with regards to TBM operation. “We overcame the rock by adapting driving parameters to the different geology, cutter wear and vibrations of the machine. We had regular maintenance, but most important of all we got really good at changing the cutters, with times down to 10 minutes per cutter change, which couldn’t have been done without good team work,” said Andersson.

It was the many cutter changes that prompted the close-knit team of LNS and Robbins to look for a better solution. “Extremely hard rock (above 250 MPa/36,300 psi) will always be a great challenge for any cutter. The very special features of the rock encountered combined with the extreme hardness made us go back to the Robbins Cutter Department to develop special cutter rings for the project. These rings increased the cutter life significantly for the project and contributed to the good production,” said Sindre Log, General Manager of Robbins Norway. 

Kare Solhaug of Robbins Field Service stands proudly in front of the 7.2 m (23.6 ft) diameter TBM on the day of its breakthrough December 10, 2015. Photo credit: LNS

Robbins Main Beam machine was launched in January 2014 and overcame incredibly hard rock, water inflows, and more. Photo credit: Statkraft

The Robbins TBM was launched following Onsite First Time Assembly (OFTA) in January 2014, less than twelve months after contract signing, and was from the outset designed for hard rock conditions. A Measurement While Drilling (MWD) system was included to analyze the ground conditions ahead of the TBM, while probe drilling was done systematically throughout the project. “This is a strong and simple machine ready to tackle hard rock conditions, but also designed to handle softer rock, which allowed for fast excavation. We had good support from competent Robbins field service,” said Andersson.


After all the obstacles, it was clear that the breakthrough ceremony celebrated a triumph of teamwork as well as a new chapter for TBMs in Norway. “Our whole jobsite was gathered for the event: LNS management, representatives from Robbins, and our client Statkraft. People said it was the best breakthrough event they had seen,” said Andersson. Now that tunneling is complete, project owner Statkraft will work to commission the tunnel and fill it with water by spring 2016.

Courtesy:- www.TheRobbinsCompany.com

Robbins Advancing the TBM Industry since 1952

Olden memories........

In 1952, James S. Robbins developed the first modern tunnel boring machine for the Oahe Dam Project in South Dakota, USA.

James S. Robbins stands in front of an early TBM excavation face showing kerf cutting.

In 1964, The Robbins Company developed the precursor to all modern EPB and Slurry TBMs for the Paris RER Metro.

The epic Channel Tunnel excavation utilized multiple Robbins EPB and Double Shield TBMs to bore below the English Channel.

Dave Leipham, retired Robbins Field Service Superintendent, inspects a cutterhead in Norway, circa 1980s.

Photo Courtesy: www.TheRobbinsCompany.com

Robust Rock Machine is a Workhorse of the TBM World

Robbins Main Beam ramps up at Mid-Halton Outfall Tunnel

On July 22, 2015, a 3.5 m (11.5 ft) Robbins Main Beam TBM began a new chapter in its storied 32-year career. Originally built for the Terror Lake project in Alaska, the veteran machine has been used all over the world, most recently in Hong Kong.  Including its new 6.3 km (4.0 mi) long tunnel for the Mid-Halton Outfall in Ontario, Canada, the machine will have bored nearly 30 km (18.6 mi) of tunnels since 1983.

Officials from the Mid-Halton Region visit the hard-working Robbins Main Beam, nicknamed “Peggie” in the Solon, Ohio, USA manufacturing facility. Photo Credit: Michelle Hill, NASTT. 

The machine’s latest endeavor will not be without challenges.  The rebuilt TBM has been beefed up for high-capacity tunneling in hard rock. Geology is expected to consist of laminated shale with interbedded limestone and siltstone layers and a maximum rock strength of 120 MPa UCS.  “We have kept this a simple, streamlined Main Beam machine, but we modified the cutterhead with larger muck buckets, so material can be moved through it faster,” explained Robbins Project Manager Lynne Stanziale.  In addition the TBM was outfitted with fully modernized VFDs, electronics, and high-capacity gearing and motors. The back-up system was also modified to make it more mobile through two 130 m (427 ft) radius curves that the TBM will have to navigate, one in each direction.

“The concept of using refurbished TBMs bears great opportunities for value-for-money constructors,” said Christian Zoller, Commercial Project Manager for contractor STRABAG.  “Our TBM ‘Peggie’ is evidence of that--when well-maintained and professionally refurbished, the lifespan of these machines is extensive. We’re pleased to see that our client Halton Region has the forward-oriented mindset that allows STRABAG to provide its renowned high level of skill and quality, paired with the good value for money that a refurbished TBM yields.”  

Contractor STRABAG, who has had several projects in Canada including the epic Niagara Tunnel project, is in charge of the works.  In addition to the tunnel, STRABAG had to construct two deep shafts for the launch and exit of the TBM.   The scheme involves two sections of tunnel designed to carry treated effluent water from a treatment plant in Oakville into Lake Ontario.  The completed system will upgrade water treatment capacity in the Halton Region of Ontario.

The Robbins Main Beam TBM has been in service since 1983, and with its new project for the Mid-Halton Outfall, it will have bored nearly 30 km (18.6 mi) of tunnels.

The TBM was launched from a 12 m (39 ft) diameter, 62 m (203 ft) deep shaft and is ramping up production, having excavated over 300 m by early September 2015.  “An ongoing challenge associated with the tunneling on this project is the requirement to drive the TBM downhill for the first 4 km (2.5 mi) of the tunnel. Keeping the water that infiltrates the tunnel from flowing directly to the cutterhead requires significant effort,” said Terry McNulty, Technical Project Manager for STRABAG.

 Management of water inflows is not the only challenge. A portion of the drive will curve to run directly under Lake Ontario for 2.1 km (1.3 mi), though the tunnel is deep enough that it will remain in bedrock. Once the machine has completed its final bore under Lake Ontario, it will be backed out of the blind heading and removed from an 8.0 m (26 ft) diameter shaft in a local park.  

Contractor Strabag lowers the main beam of the Robbins TBM into the 62 m (203 ft) deep launch shaft.

“We can already see the potential performance that this TBM will have, once fully assembled and tested. We look forward to the continued support and cooperation with our partner Robbins on this endeavor,” said Zoller.  Though the TBM has only recently started up, crews are moving forward with a plan to line the tunnel with mesh panels and ring beams if necessary.  A cast-in-place liner will follow on after tunneling is completed in August 2017. 

Breakthrough Robbins Machine Breaks Through

“Crossover” TBM Completes Mine Tunnels

                                       A ground-breaking TBM brought a mining operation one step closer to first coal on February 9, 2015.  The Robbins Dual Mode “Crossover” Rock/EPB TBM completed tunneling at Anglo American’s Grosvenor Project in Queensland, Australia. The “Crossover” designation is new for Robbins Dual Mode TBMs, and will be used for all such projects going forward.  The efficient type of TBM used at Grosvenor is now known as an XRE, standing for Crossover between Rock/EPB. Other types of machines are designated the XSE (Crossover between Slurry/EPB) and the XRS (Crossover between Rock/Slurry).

The Grosvenor Mine, a Greenfield coal operation, was the first to utilize TBM technology for mining tunnels in Queensland.  Mine owner Anglo American Coal chose the 8.0 m (26.2 ft) machine for two decline access tunnels at grades of 1:6 and 1:8, one for conveyors and another for people and equipment.

 

The Robbins Crossover Rock/EPB was launched in December 2013 following Onsite First Time Assembly (OFTA) at the jobsite

The XRE TBM was picked over the traditionally-used roadheader method for several reasons, including excavation speed and tunnel maintenance. The choice proved prescient with the machine excavating at a rate approximately ten to fourteen times faster than a roadheader—about 70 m per week for the TBM vs. 5 m per week for a roadheader. In addition, the final tunnels have a smooth profile and are segment-lined, requiring minimal upkeep during the planned 40-year life of the mine. “In the coal mining community, and certainly in Queensland, companies are aware of the Grosvenor project and how it has set a benchmark for underground access drift construction,” said Glen Maynard, Robbins Field Service Site Supervisor at Grosvenor.

 

Rates of tunneling for the Robbins Crossover TBM were fourteen times faster than that of a traditional roadheader excavation Image: Courtesy of Anglo American

The machine’s Crossover capabilities enabled it to operate in both hard rock and mixed ground. In addition, the TBM was required to operate during gaseous conditions.  The unique TBM design included a cutterhead capable of interchanging hard rock and soft ground cutting tools, a two-stage center-mounted screw conveyor, a “quick removal” shield system, and flame-proof machine components due to the possibility of methane gas in the underground environment.

The TBM was optimized for hard rock and mixed ground excavation in geology ranging from soft clay and soil to sandstone and basalt. The two-stage screw conveyor worked in both ground conditions to draw muck from the tunnel face. Two sets of shields were built for the TBM’s “Quick Removal” system, and were detached from the machine at the end of each blind tunnel to be left in the ground for constant support, a requirement in Australian tunnels. The inner core components of the TBM were then retracted out of the segment-lined tunnels on specially designed transport dollies.

The machine began boring the conveyor tunnel in December 2013, and after completion in May 2014 was successfully retracted and transported to the second tunnel site. The machine was then re-commissioned for the people and equipment tunnel in November 2014 with a new set of shields. Once excavation commenced, boring was completed in 88 days at an average of 10.9 m per day, with a best day of 25.2 m. The bore itself was similar to the first, with few challenges encountered other than elevated methane gas levels that required several temporary stoppages in order to safely remove the gas from the tunnel. “The machine performed very well and had high reliability. The cutting tools, in particular the knife edge bits, were exceptional. The bits were required for most of the drive and one complete set lasted 650 meters,” said Maynard.

 

The Robbins Crossover Rock/EPB machine completes tunneling on February 9, 2015. Image: Courtesy of Anglo American

The team is now preparing the machine for its final retraction and roll-out, and it will be on the surface in less than two months.  The TBM will then be stored onsite for future Anglo American mining projects.

 

Workers from owner Anglo American celebrate the breakthrough of the Robbins Crossover Rock/EPB machine on February 9, 2015. Image: Courtesy of Anglo American

Once the longwall mine is operational in 2016, Grosvenor is expected to produce five million tonnes of coal per year over the next 26 years.

Announcing the Crossover Series of Robbins TBMs

Dual Mode Machines bridge the gap in Mixed Ground

                                                                 

The Robbins Crossover Series of TBMs includes the XRE (Rock/EPB) machine, a TBM type that recently completed swift tunneling at Australia’s Grosvenor Decline project.

                                         

Robbins proudly announces its Crossover Series of TBMs, a line of field-tested, rugged Dual Mode-type machines.  Crossover TBMs feature aspects of two TBM types, and are ideal for mixed ground conditions that might otherwise require multiple tunneling machines.  The XRE (standing for Crossover Rock /EPB) is the most common type of hybrid machine, and features characteristics of Single Shield Hard Rock machines and EPBs for efficient excavation in mixed soils with rock.  An XRE TBM recently completed tunneling at Australia’s Grosvenor Decline Tunnel, where it excavated two mine access drives at rates fourteen times faster than a traditional roadheader.  The latest drive was completed on February 9, 2015. “This was a big step forward for the mine to appropriately use civil tunneling technology for a mining application. I take my hat off to the management of owner Anglo American Coal to have the foresight and leadership ability to take this step. Using the Crossover technology [versus the traditionally-used roadheader method], the project was finished on schedule,” said Lok Home, Robbins President.

Additional types of Crossover machines include the XSE (Crossover between Slurry/EPB) and the XRS (Crossover between Rock/Slurry) TBMs.  The Crossover series is quickly gaining in popularity, with Robbins Crossover TBMs currently being assembled in Mexico, Turkey, and Azerbaijan.  An XRE TBM will begin excavation for Mexico’s Túnel Emisor Poniente II (TEP II) later this year, while an XSE is being readied for excavation at the Baku Metro.

 

The Robbins Crossover (XRE) TBM pictured here is at the forefront of a trend for efficient machines that can operate in mixed ground conditions.

The rebranding and Crossover terminology embodies the concept that the machines are able to cross over between modes, says Home. The unique machines are a top focus point for the company: “Robbins comes at this business with extensive rock experience so everything we design comes with the assumption that there will be tough conditions. When you have to “cross over” to another mode then already you are in difficult conditions, and contractors need robust machines to get through these challenges,” says Home. 

Home foresees that machine sales will grow as more projects worldwide are planned in difficult and varying ground conditions. Survey results back up the trend, indicating an increased interest in Crossover-type machines worldwide. “This is a continuous evolution and we are consistently endeavoring to improve Crossover designs. We have three of the machines in production now and I see this number increasing year by year as the industry sees and accepts their value.”

Robbins teams up to bring Embattled TBM back to Life

Small Siphon Tunnel overcomes Long Odds in NYC

The EPB, originally manufactured by CAT, was launched in August 2012 for the Tully/OHL JV

On January 28, 2015, about 35 m (115 ft) below New York Bay, a celebration was underway.  Workers from the local tunnelers union in New York City, USA, known as the Sandhogs, completed the last meters of tunnel alongside workers for subcontractor Tully/OHL and Robbins field service.  The team had many reasons to celebrate—not only had their TBM just completed a much-needed undersea tunnel, but it had also done so after a near-catastrophic natural disaster, extensive rebuild and geologic complications.

The New York City Harbor Siphons Project began simply enough—the 2.9 km (1.8 mi) long tunnel between Brooklyn and Staten Island was designed to replace two existing shallow water lines below the bay.  The project, managed by the New York City Economic Development Corporation (NYCEDC), replaces the lines with the deeper siphon in order to make way for a larger project—the dredging of the Anchorage Channel. The channel (part of New York Bay) is an important waterway for shipping, and its dredging will allow for mega ships carrying large cargo loads to pass through.

Tully/OHL USA JV procured a 3.8 m (12.5 ft) diameter EPB TBM from Caterpillar in 2012.  The TBM, dubbed “Pat”, was designed to drive through highly variable clays, sands, weathered rock and boulders. It was launched from the 35 m (115 ft) deep Staten Island shaft, boring towards the 40 m (131 ft) deep Brooklyn shaft, in August 2012.

The Robbins Field Service crew worked to bring a flood-stricken EPB back online at the Harbor Siphons project, which completed tunneling in January 2015.

 

In October 2012, the unexpected happened: a massive hurricane, dubbed Superstorm Sandy, barreled down on the U.S. East Coast with winds up to 145 kph (90 mph).  Extreme flooding at the waterfront jobsite in Staten Island overtopped protective concrete barriers that had been designed three feet above the 100-year flood level.  Seawater rushed into the tunnel and the nearly 113 m (370 ft) long machine was entirely submerged only 460 m (1,500 ft) into its drive. “Obviously this was our biggest challenge,” said Luis Alonso, Tunnel Manager for OHL. “After that, not many people thought we would be able to finish this tunnel.”

After floodwaters began to recede, OHL set about determining the extent of damage on the machine. The TBM was severely corroded by saltwater and sat idle until July 2013. During that time, CAT announced its impending closure of its TBM business, and the contractor looked to other manufacturers. “OHL was always determined to finish this project.  After studying other options, we decided to proceed with the full refurbishment of the TBM with the help of The Robbins Company. The whole crew worked together to achieve that goal,” said Alonso.

The Robbins Field Service Team replaced all electronics systems, rebuilding much of the CAT-manufactured EPB from scratch

 

Robbins coordinated the effort to replace corroded hydraulic components and all new electrical systems in mid-December 2013.  Electrical systems had to be reverse-engineered, while the PLC had to be entirely redesigned. The refurbishment also centered on removing the rear eleven gantries and belt conveyor to be cleaned, evaluated and repaired. The rebuild took about four months, much of it done in the tunnel under water pressure, and crews were able to return to mining on April 14, 2014. 

To ensure that the project stayed on the incline to success, Robbins Field Service personnel remained onsite to support ongoing maintenance of the TBM. With their help, machine performance steadily increased, eventually reaching rates as high as 30.48 m (100 ft) per day and as much as 25 rings in 24 hours in August 2014.

Workers from the local tunnelers union, known as the Sandhogs, celebrate as the EPB breaks into the slurry wall of the exit shaft

 

As excavation picked up, ground conditions changed from marine sediments (clay, silt and sand) to glacial geology with sand, exceptionally hard boulders, and excessive water ingress, resulting in slow propulsion rates. “The TBM needed more thrust and we decided to implement four additional auxiliary cylinders. Robbins field service helped in developing the size, features and location of the cylinders, which were eventually placed in the lower quadrant of the propulsion system,” said Alonso. With the new system crews were able to re-establish forward progress. The constant hurdles continued into early October when a hyperbaric intervention at 4 bar of pressure was required to change the cutting tools in a pocket of glacial soils. Despite the new obstacles, the crew was able to steadily increase the rate of excavation to 5 to 7 rings per day. 

“This tunnel is an important part of a larger project, and we are proud to be doing what we do every day, dealing with troubles as they come up, until we reach the end of the drive,” said Alonso.  Now that tunneling is complete, the stationary and tail shields will be buried at the exit shaft entrance, with the cutterhead and back-up being removed. 

 

The successful project overcame multiple obstacles—flooding at the harbor-side jobsite overtook 100-year flood barriers and submerged the machine in 2012